LCT and neoplasm: At 24 h we observed no changes in the Lac/Pyr ratio for all tumor types following 6‐Gy radiation, a finding similar to that of Day et al., who treated C6 bearing rats with a single dose of 15 Gy and showed a trend, but nonsignificant drop in Lac/Pyr at 24 h that became significant at 72‐h postradiation.35